Centrifugal filter, particularly for lubrication oil of internal combustion engines



1961 D. GIACOSA 3,014,643

CENTRIFUGAL FILTER, PARTICULARLY FOR LUBRICATION OIL OF INTERNAL COMBUSTION ENGINES I Filed June 10, 1957 4 Sheets-Sheet 1 53 48 l 1 80a 52 14 luzd 42C 3 ,7 !g H 2| .v-

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39d M W d sh 41 386 O 80 1 4 54 49 4 AZa 4'2 55 Dec. 26, 1961 D. GIACOSA 3,014,543

CENTRIFUGAL FILTER, PARTICULARLY FOR LUBRICATION OIL OF INTERNAL COMBUSTION ENGINES Filed June 10, 1957 4 Sheets-Sheet 2 Dec. 26, 1961 D. GIACOSA ,0 4 64 CENTRIFUGAL FILTER, PARTICULARLY FOR LUBRICATION OIL OF INTERNAL COMBUSTION ENGINES Filed June 10, 1957 4 Sheets-Sheet 3 Dec. 26, 1961 D. GIACOSA 3,014,643

CENTRIFUGAL FILTER, PARTI ARLY FOR LUBRICATION on OF INTERNAL co STION ENGINES Filed June 10, 1957 4 Sheets-Sheet 4 United States Patent 01 CENTRHFUGAL FELTER, PARTICULARLY FQR LU- BRICATIGN OH OF INTERNAL CUMBUSTHQN ENGINES Dante Giacosa, Turin, ltaly, assignor to Fiat Societa per Azioni, Turin, Italy Filed lune 10, W57, Ser. No. 664,691 Claims priority, application Italy Oct. 31, 1956 2 (Ilaims. (QR. 23332) This invention relates to a centrifugal separator particularly designed for lubrication oil of internal combustion engines.

The invention has the purpose of making available a separator of this type equipped with means suitable to permit a substantial increase of the performance of the separator itself.

The centrifugal separator in accordance with the invention is characterised by the fact that it comprises at least one annular chamber whose inlet communicates with the area of oil flow, but in such a Way that the oil is not compelled to flow across said annular chamber.

The invention will be described with reference to the accompanying drawing, wherein similar characters of reference designate corresponding parts, and wherein:

FIG. 1 is a longitudinal section of the centrifugal separator constructed in accordance with the invention.

FIG. 2 is a longitudinal section of the separator casing.

FIG. 3 is a front view of the casing in the direction of the arrow F shown in FIG. 2.

FIG. 4 is a front view of a cover element for the separator casing shown in FIGURES 2 and 3.

FIG. 5 is a longitudinal section of said cover element taken on line V-V of FIG. 4.

FIG. 6 is a plan view of a structural detail of the separator.

FIG. 7 is a section taken on line VlIViI of FIG. 6.

FIG. 8 is a plan View of another structural detail of the separator.

FIG. 9 is a section taken on line IXIX of FIG. 8.

FIG. 10 is a section taken on line X-X of FIG. 8.

The end of an internal combustion engine crankshaft is indicated by Z. The crankshaft front main bearing 3 is installed between engine crankcase 1 and a lower cap 4 secured to the crankcase by means of screws 51).

Crankshaft 2 is provided with an extension 212 on the end of which is mounted a centrifugal separator comprising a bell-shaped casing 42 fitted with vanes 42a and a cover 8t secured to casing 42 by means of screws 44.

The coupling of be1l-shaped casing 42 with extension 2b is obtained by a key 12 located in a recess provided in the periphery of the extension 2b and projecting into a groove 42c formed in the hub 42d of the casing 42.

The oil to be filtered is fed through a groove 38c machined in the body 33a of a gear pump (not shown in the drawing), flows across radial ducts 390 of extension 2b, passes into an annular duct 4th defined by the surface of an axial hole bored in the extension 2b of the crank shaft reaching by its end portion 2a into the shaft portion journalled in the main bearing 3 and a pipe 41 fitted by its one end into the end portion 2c of said hole and flared at its other end at 41a in order to intercept communication between the duct 4th and the outlet of the hole bored in the extension 2b. The duct communicates with theinside .of the separator through radial bores in the fore end 2d of the extension 2b, which are aligned with recesses 4215 cut in the front of the hub 42d carrying the bell-shaped casing of the separator.

The oil leaves the separator flowing through the inside of the pipe 41 and through the end portion 20 of the hole in the extension 2b and reaches a channel 21' bored in the crank of the shaft for being conveyed to the main bear- 3,614,643 Patented Dec. 26, 1961 ings of the crank shaft and a radial duct 51 communicating through an opening in the bearing 3 with a bore 52 drilled in the crank case 1 to be conveyed towards the valve operating mechanism and other engine parts requiring lubrication. Element 49 is the crank shaft gear, which is keyed on the extension 2b by means of a key 12 and meshes with the camshaft timing gear 48. The gears 49 and 48 are separated from the separator body by means of a cover 53 sealed against the hub 42d by the gasket 5 and abutting a rubber seal 55 located in a groove provided in the upper edge of the oil pan 56.

In the embodiment of the invention shown in the drawing, the separator is of the type in which the oil first flows in a radial section towards the outside and, subsequently, a radial section towards the inside, where in the first section takes place the settling on separator walls of contaminants having a higher-than-oil specific gravity.

The two sections are kept separate by a disc-type diaphragm 82 installed on the end of crank shaft extension 21;.

According to the invention, inside the separator is formed an annular chamber concentric to the separator itself and so arranged that its inlet communicates with the area of oil flow but in such a way that the oil is not compelled to cross said annular chamber.

The chamber is obtained by interposing between separator body 42 and cover 80 an annular diaphragm 81 whose opening has a diameter substantially smaller than the outer diameter of the disc-type diaphragm 82; since cover 80 is dished, between the latter and annular dia phragm 81, is formed a chamber litz which, from results obtained in practical test runs, has proved to remarkably increase separator performance. In fact, the range of centrifugal force in said chamber is very high whereas the speed of oil flow is practically negligible and consequently the contaminants having a specific gravity greater than that of the oil which are deposited in said chamber as an effect of centrifugal force are not entrained by oil flow as may instead happen in the main chamber.

At the same time, the presence of the annular diaphragm 81 causes an abrupt reversal in the direction of flow of the oil coming from the main chamber, resulting in an additional centrifugation of suspended contaminants.

Diaphragm 81 has the further purpose of eliminating all vortices in the settling zone upstream of the diaphragm.

As another added advantage, diaphragm .81 facilitates the installation of diaphragm 82 on crank shaft extension 22:; in fact, said disc-type diaphragm 82 may be' axially held on one end by the edges of vanes 42a of casing 42 and, on the other end, by said annular diaphragm 81 itself by abutting on formed ribs 32a of the disc diaphragm.

it will be understood, of course, thatthe invention is not regarded as being limited in scope and principle, but includes all changes and modifications coming within the terms of the illustrations given and claims hereof.

Thus, for instance, instead of being obtained by means of an annular diaphragm 81, annular chamber 80a may be obtained by casting with another form of separator; also, if desired, a number of chambers 89a may be had in order to increase separator efiiciency.

What I claim is:

1. An improved centrifugal separator for cleaning lubricating oil and, more particularly, lubricating oil used in internal combustion engines, said separator comprising in combination: a rotating shaft, having an end, defining oil ingress and egress ducts, each duct having oil discharge and receiving ends, said ingress duct discharge end being axially spaced inward from the end of said shaft and from said egress duct receiving end; a bell shaped casing, defining an interior space and having-an open .end and a closed end with a center hub in the closed end, mounted by said hub on said shaft for rotation therewith with said casings open end being positioned axially beyond the shaft end; a plurality of vanes radially mounted and fixed in said casing, each said vane extending radially between said center hub and said casing and axially between said open and closed ends of said casing, said vanes for guiding and impelling the oil in the casing radially outward; a disc diaphragm, having a perimeter, mounted on said shaft in said casing intermediate said ingress duct discharge end and egress duct receiving end and extending normal thereto and radially outward toward and short of said casing to transversely divide said casing interior space into an axially inner section and an axially outer section connected by the peripheral space between the perimeter of said disc diaphragm and said casing; channeled means defining bores connecting said axially inner section with said ingress duct discharge end for the ingress of oil to said interior space and said egress duct receiving end opening directly into said axially outer section for the egress of clean oil from said interior space; a cup shaped cover for closing said casing open end and interior space; an annular diaphragm mounted between said casing and said cover and spaced axially outward from the end of said shaft and disc diaphragm to extend radially in said casing interior space parallel with said disc diaphragm to overlap the perimeter of said disc diaphragm and thereby baffle the peripheral space connecting said two sections and to form with said cup shaped cover a radially inward opening peripheral chamber,

whereby dirty oil delivered through said ingress duct discharge end to said axially inner section of said casing space is centrifugally thrown radially outward by the rotation of said shaft, casing and impelling guide vanes and through said connecting peripheral space into said axially outer section, the heavy impurities in the dirty oil being carried around the bafiiing annular diaphragm up into said radially inward opening peripheral chamber and the lighter clean oil being deflected by said baffling annular diaphragm radially inward to said shaft egress duct receiving end for return to engine lubrication.

2. A separator in accordance with claim 1, characterized by the fact that the disc diaphragm is mounted centrally on the end of the shaft and peripherally against the annular diaphragm through at least three radial ribs.

References Cited in the file of this patent UNITED STATES PATENTS 1,887,955 Reeves et a1 Nov. 15, 1932 2,083,809 Asch June 15, 1937 2,645,415 Strezynski July 14, 1953 2,741,333 Dega et a1. Apr. 10, 1956 2,865,562 Burke Dec. 23, 1958 2,908,352 Giacosa Oct. 13, 1959 FOREIGN PATENTS 113,848 Sweden Apr. 17, 1945 607,994 France Apr. 10, 1926 630,986 France Sept. 3, 1927 

